3D Inclinometer and MEMS Acceleration Sensors

Currently different systems are used to estimate simultaneously linear and angular positions of a mobile frame. This paper presents a novel approach to deduce simultaneously the aforementioned functionalities with only one sensor module. The use of only four MEMS accelerometers represents the main advantage of the proposed system. These accelerometers are mechanically mounted to form an orthogonal frame. The angular positions are determined from earth´s gravity orientation in the mobile frame. The inclinometer module does not measure horizontal plane rotations, for this reason, plane angular speeds are estimated from the amplitude of the normal acceleration resulting from this type of rotation. Moreover, an angular encoder and a gyroscope are attached at the bottom of the module in order to compare and validate the estimated angular speed in plane rotations. Although this solution can be less precise, it can be an alternative to the expensive products found on the market